Center break high voltage switch with circuit interrupters



July 13, 1965 J, J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July26, 1962 6 Sheets-Sheet 1' July 13, 1965 J. J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July26, 1962 6 Sheets-Sheet 2 July 13, 1965 J. J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July26, 1962 6 Sheets-Sheet 5 July 13, 1965 J. J. MIKOS 3,194,928

CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July26, 1962 6 Sheets-Sheet 4 .W/ ,f WWW A mfiii 67 25} k R. @57 8 60 (39 67I July 13, 1965 J. J. MIKOS 3,194,928

' CENTER BREAK HIGH VOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS Filed July26, 1962 e Sheets-Sheet 5 J. J. MIKOS July 13, 1965 CENTER BREAK HIGHVOLTAGE SWITCH WITH CIRCUIT INTERRUPTERS 6 Sheets-Sheet 6 Filed July 26,1962 5 u Q I m\\ mkwwbb m9 g t QSQ i United States Patent 3,194fi28CENTER BREAK HIGH VULTAGE SWITCH Wiiitl CIRCUIT INTERRUPTERS' John J.Milros, Highland Paris, lll., assignor to S dz (1 Electric Company,Chicago, 1th, a corporation of Delaware Filed July 26, 1962, Ser. No.212,613

g Claims. (crass-14s) This invention relates, generally, to electricswitches and it has particular relation to such devices for use inelectric power circuits operating at voltages of the order of 230 kv.although it is not limited to this particular voltage. It constitutes animprovement over the switch constructions shown in U.S. Patent No.3,030,481, issued April 17, 1962, to W. A. Gussow and John I. Milros,and shown in application Serial No. 111,998, filed May 23, 1961, by JohnMikes and Leonard V. Chabala, now Patent No. 3,163,736.

Among the objects of this invention are: To provide in a new andimproved manner for opening an electric power circuit operating at avoltage of the order of 230 kv. and carrying load current; to accomplishthis within a minimum of space considering the basic insulation level(BIL) that is required to be maintained is of the order of 900 kv. to1,300 kv.; to employ disconnect switch blades that have relatively lowmoment of inertia to facilitate their movement to open circuit positionfor introducing an air gap in the circuit and from open to closedcircuit position; to resist in a simple and eificicnt manner the shockincident to the impact of the rotating parts at the ends of theirmovements in the switch open and switch closed positions; to employ apair of pivot-ally mounted disconnecting switch blades arranged toengage and disengage at their distal ends in series with circuitinterrupter means and to sequentially operate the construction to theend that the circuit is open by the interrupter means followed byseparation of the distal ends of the switch blades to provide thedesired air gap and the circuit is closed by closing the interruptermeans and then engaging the distal ends of the switch blades to completethe circuit; to provide for maintaining a circuit through the switchblades during the initial portion of their opening movement and thefinal portion of their closing movement; to close the interrupter meansduring the continued opening movement of the respec tive switch blade sothat when the switch blades are fully open their interrupter means arefully closed; to provide a circuit interrupter in series with eachswitch blade at the hinge end of each single pole switch assembly and tosynchronize the opening and closing of the circuit interruptcrs witheach other and with the operation of the switch blades by directmechanical coupling of rotating insulator supports carrying theindividual switch blades and interrupter mechanisms whereby the circuitis opened simultaneously at two places by the circuit interruptersfollowed by separation of the switch blades; to provide a single circuitinterrupter in series with one of the switch blades at its hinge end toopen the circuit followed by introduction of an air gap by separation ofthe switch blades; to provide stop means individual to each switch bladefor arresting its opening and closing movements, the stop means beingresilient to facilitate absorbing the shock incident to such operations;to mount each switch blade on a rotatable insulator and to provideadditional stop means at the base of each insulator for arresting itsopening and closing movements; and to provide a polyphase switchconstruction comprising a plurality of switch pole units, one for eachphase, and to employ common means for effecting simultaneous operationof these several poles.

ground 12 a distance in accordance with the 3,1943% Patented July 13,1965 in the drawings:

FIG. 1 is a top plan view of a support structure for a polyphase switchinstallation, the switches being omitted and only their stationary androtatable supports being shown.

Fit 1A is a view, at an enlarged scale, showing certain details ofconstruction of the rotatable insulator supports and stops therefor.

FIG. 2 is a view, inside elevation, or" the support structure shown inFIG. 1.

FIG. 3 is a top plan view of one pole of a polyphase switch constructioninwhich the present invention is embodied, it being understood thatthree poles, identical with the construction shown in FIG. 3, areemployed and are mounted on the switch operating structure shown in FIG.1.

FIG. 4 is a view, in side elevation, of the switch pole as shown in FIG.3, the distal or contact engaging ends of the switch blades being shownsomewhat diagrammatically in order to avoid complicating the drawingwith the contact structure and corona shield arrangement carriedthereby.

FIG. 5 is a view, at an enlarged scale, andvin part in section showingthe construction of the stop mechanism that is associated with the rightswitch blade and being a duplicate of the construction used for the leftswitch blade.

FIG. 6 is a horizontal sectional view taken generally along the line 6-6of PEG. 5.

FIG. 7 is a perspective view of the switch pole construction shown inF168. 3 and 4-, the supporting base structure not being shown, theswitch blades being shown in the closed position and an alternate stopmechanism employing a torsion bar construction being shown.

FIG. 7A is a horizontal sectional view taken generally along the line7A-'7A of FIG. 7 to show in more detail the particular stop constructionthere employed.

FIG. 7B is a top plan view, at an enlarged scale, of the coronashieldssand contact arrangement at the ends of the switch blades inclosed position.

FIG. 7C is a view, in side elevation, of the construction shown in FIG.7B. 7

FIG. 8 is a view, similar to FIG. 7, taken at a slightly different angleand showing the switch blades in the open position. 7

FIG. 9 is a view of an underhung switch construction employing certaindetails of the present invention including a center break constructionwith a single circuit interrupter associated with one of the switchblades;

FIG. 10 is a bottom plan view of the construction shown in FIG. 9.

Referring now particularly to FIGS. 1 and 2 of the drawings, it will beobserved that the reference character It} designates, generally, asupport structure for a polyphase switch comprising three poles ofidentical construction the general details of which will be describedhereinafter. The support structure 1% includes frame uprights 11 thatextend into the ground indicated at 12. They are interconnected bylongitudinal. frame members 13 to provide a rigid support structure withthe longitudinal frame members 13 being elevated above the voltagerating of the switch structure to be described. it will be understoodthat other support structures can be employed and that the particularconstruction shown and described herein is byway of illustration only.

Extending across the longitudinal frame members 13 are three pairs oftransverse support channels 14-14, each pair being employed to supportone pole of the polyphrase switch structure. Stationary insulatorsupports l515 are mounted at the ends of each pair of support channels14-14 for receiving stationary insulators to be described. Intermediatethe stationary insulator supports 15-15 are rotatable insulator supports16-16 which are suitably mounted in bearings on the transverse supportchannels 14-14. There are two rotatable insulator supports 16-16 foreach switch pole and they are provided with radially extending operatingarms 17-17 that are interconnected by an operating link 18. The ends ofthe operating link 18 are pivotally connected at 19-19 to the respectiveoperating arms 17-17.

It is desirable that provision be made for limiting the rotary movementof the rotatable insulator supports 16- 16 and parts rotatabletherewith. For this purpose, as shown more clearly in FIG. 1A of thedrawings, the rotatable insulator supports 16-16 are provided withdeteuts 20-20 which are arranged in the switch closed position to engageadjustable stops 21-21 in the form of screws and in the switch openposition to engage adjustable screws 22-22. The adjustable stops 21-21are carried by stop angles 23-23 mounted on one of the adjacent supportchannels 14 while the stop screws 22-22 are mounted on similar stopangles 24-24 mounted on the support channels 14-14.

Referring again to FIG 1, it will be observed that one of the rotatableinsulator supports 16 for each switch pole is provided with a secondoperating arm 27 that is pivotally connected at 28 to one and of a link29 the other end of which is pivotally connected at 311 to an arm 31which is rotatable with a yoke 32 that is rotatably mounted about anaxis 33 on the transverse support channels 14-14. The three yokes 32 areinterconnected by interphase rods 34-34. It will be observed that therespective ends of the interphase rods 34 34 are pivotally connected at35-35 to the ends of the yokes 32. An operating rod 37 extends from theleft yoke 32, for example, and is connected to one arm of a bell crank33 that is pivoted at 39 on the support structure 10. The other arm ofthe bell crank 38 is connected to a connecting rod 40 which extends toand is operated by a switch operator 41 which may be of any suitabletype such as that shown in US. Patent No. 2,796,478, issued June 18,1957, to John J. Mikos.

When the switch operator 41 is energized to move the connecting rod 40downwardly in the direction indicated by the arrow 42, FIG. 2, thearrangement is such that the insulator supports 16-16 for each switchpole are rotated in opposite directions to initiate opening movement ofdisconnecting switch blades. However, before the circuit through theswitch blades is opened, circuit interrupters are tripped to open thecircuit at two places followed by separation of the switch blades toprovide an air gap and then, as a part of the continued opening movementor downward movement of the connecting rod 40 under the control of theswitch operator 41, the spring mechanism associated with each circuitinterrupter is reloaded and the contacts of the respective circuitinterrupter are reclosed. On operation of the switch operator 41 in areverse direction to move the connecting rod 443 upwardly or in adirection opposite to the arrow 42, the insulator supports 16-16 foreach switch pole are rotated in opposite directions and opposite to thedirections in which they previously rotated for the purpose of closingthe circuit by causing the switch blades to engage at their distal ends.

The details of construction of one of the switch poles are shown moreclearly in FIGS. 3 to 8 of the drawings to which reference now will bemade. Here the reference character 44 designates, generally, a switchpole construction which includes stationary insulators 45-45 that aremounted on the stationary insulator supports 15-15 which are carried bythe transverse support channels 14-14 near their ends. In the particularconstruction shown the stationary insulators 4-5-45 extend upwardly andthey carry line terminals 45-46 at their upper ends for connection toline conductors. Mounted on each or" the line terminals 45- 16 is acircuit interrupter that is indicated, generally, at 4'7 and may be ofthe construction disclosed in the patent first above referred to or inthe application above referred to. Each circuit interrupter 47 includesseries connected main separable contacts 48-48 and series connectedauxiliary separable contacts 4-9-49 as shown by broken lines in theright circuit interrupter 47 shown in FIG. 4. As pointed out in thepatent and application just referred to, provision is made in theoperation of the circuit interrupter 47 to open a circuit for firstopening the main separable contacts 4-5-48 and then opening theauxiliary separable contacts 49-4-9 to effect thereat the final circuitinterruption. Auxiliary trip means also can be employed, as disclosed inapplication Serial No. 172,017, filed February 8, 1962, by Sigurd I.Lindell and Leonard V. Chabala, for tripping the circuit interrupter 4'7simultaneously to open the circuit thereby at two places. Since thedetails of construction of the circuit interrupters 47-47 and the mannerin which they are operated are all as set forth in the patent andapplications just referred to, no further description thereof will beset forth herein.

At the ends of the circuit interrupters 47-47 away from the lineterminals 45 45 there are provided metallie mechanism housings 50-50through each of which a shaft 51, FIGS. 5 and 6, extends. The shaft 51,individual to each mechanism housing 50-51) is mounted on and isrotatable with rotatable insulators 52-52 that are mounted at theirlower ends on the rotatable insulator supports 15-16. It will beunderstood that each metallic mechanism housing 5t) includes anoperating structure under the control of the respective shaft 51 androtatable insulator 52 for controlling the opening and closing functionsof the circuit interrupters 47-47.

Mounted on and rotatable with the upper ends of the shafts 51 are switchblades 53-53 that are arranged to have contact engagement at theirdistal ends 54-54. It will be described hereinafter how the distal ends54-54 of the switch blades 53-53 are provided with contact constructionsand corona shields.

Each of the switch blades 53-53 extends radially from hub fittings 55-55which are secured to and rotate with the respective shaft 51-51. At theupper ends of the shafts 51 there are mounted stationary terminals 56-56which are shown more clearly in FIGS. 7 of the drawings. The stationaryterminals 56-56 are connected by flexible conductors (not shown) to therespective hub fittings 55- 55 in order to provide a current carryingpath of low resistance therebetween. The stationary terminals 56- 56 areconnected to the metallic mechanism housing 50- 51 by means of L-shapedcopper bar connectors 57-57 suitably brazed to L-shaped copper barconnectors 58- 58. As shown more clearly in FIG. 5 one leg 59 of each ofthe copper bar connectors 58 overlies the respective metallic mechanismhousing 51) and is clamped thereto by means that will be describedpresently.

It will be understood that the masses of the rotating insulators 52-52and the switch blades 53-53 rotatable therewith together with the partsmounted thereon are substantial. Since these elements are rotated atrelativel y high speed, a substantial amount of energy must bedissipated at the ends of the switch opening and switch closingmovements. In part, this is accomplished by the stop constructionspreviously described and located on the respective transverse supportchannels 14-14 in connection with rotatable insulator supports 16-16.However, it is desirable to provide additional stop means for furtherabsorbing the energy incident to the arresting of the opening andclosing movements of the switch blades 53-53 and associated parts. Thisconstruction is shown more clearly in FIGS. 5 and 6 of the drawings.Here it will be observed that a circular plate 62 is associated witheach of the hub fittings 55 while a similar circular plate.

identical construction and each is provided respectively with a hub 64and 65. As shown in FIG. 6 a key 65 serves to secure the hub 65 forrotation to theshatt 51. A similar construction is employed for securingthe hub 64 to the shaft 51 above the mechanism housing 5h. Bolt holes 67are provided as shown in the plate as for mounting it on the respectiverotatable insulator 52. Similar bolt holes are provided for securing thecircular plate 62 to the underside of the respective hub fitting Thecircular plates 62 and 63 are provided with de' pending and upstandingdetents or studs 6?: which are spaced apart along a circle through adistance approximately corresponding to the extent of rotation of therespective shaft 51 and rotatable insulator 52. At the ends of theirrotation the detents or studs sa ss are arranged to engage adjustingscrews 69-69 which extend from blocks iii- 70 that are welded to thelaterally extending ends of C-shaped' support plates 71-71. The C-shapedsupport plates 71-7l are secured to the mechanism housings Eli-450 bybolts 72. which extend through a suitable spacer '73, PEG. '5, a shockabsorbing spacer M of suitable plastic material, and the leg 59 of therespective copper bar connector It will be understood that the adjustingscrews 6969 can be shifted in order to engage the respective detents orstuds 68d$ at the positions corresponding to the desired closed and openpositions of the switch blades 53-53.

If desired, either the lower or the upper circular plate 62 or 63 can beomitted with a corresponding omission of the upper or lower portion ofthe respective C-shaped support plates'l'l. The support plates 71 ofC-shape or L- shape can be of cast construction or they can be formed ofrolled steel plate as circumstances may dictate.

A torsion bar stop mechanism is shown in FIG. 7A as an alternate to thestop plate construction shown in FIGS. 5 and 6. Here it will be observedin connection with FIG. 7 that an L-shaped torsion bar 77 is providedthat may be formed of spring steel. A plate '78, corresponding to thecentral portion of the C-shaped support plate 71, is welded to the longleg 79 of the L-shaped torsion bar 77 and can be secured to therespective mechanism housing 5t by the bolts 72 in the manner previouslydescribed. The short leg Stl of the L-shaped torsion bar 77 is welded atits end to a block till which is similar to the block 7% previouslydescribed and is provided with adjusting screws til-82 for enga ing thedetents or studs 686& in the manner previously described. It will beunderstood that the torsion bar 77, instead of being L-shaped can be C-shaped as shown for the C-shaped support plates 71 with a duplicate stopmechanism being provided on the lower end.

FIGS. 78, 7C and 8 show rnore clearly the constructions at the distalends 54-54 of the switch blades 5353. Here it will be observed that acontact plate 85 is provided on one of the distal ends 54 for engagementwith contact fingers $5 on the distal end 54 of the other switch blade53 and within a sleet hood 87 to protect against ice. Arcuate outerupper and lower corona shields 8S and are carried by upper and lowerL-shaped supports 9% and 91 on the distal end 5 of one switch blade 5'3while arcuate inner upper and lower corona shields 92 and 93 are carriedby upper and lower L-shaped supports M and 95 on the distal end of theother switch blade 53. The corona shields and supports are formed ofaluminum to provide a minimum of weight.

in order to insure that the circuit through the switch blades 53-53 ismaintained during the initial portion of their opening movement and thefinal portion of their closing movement upper and lower contact fingers96 and 97, preferably of stainless steel, are mounted on the upperL-shaped support 9% in vertical and horizontal spaced relation and theyextend into contact engagement with the inner upper corona shield 92 andwell beyond it in the switch closed position. Their out turned ends 98-and SE9 facilitate engagement with the corona shield 92 when the switchblades 53 are swung to their closed position where the circuit iscompleted at this point. Since the distal ends 54 of the switch blades53 are moving at high speed in the closing operation, there is a minimumof arcing incident thereto when they close on a circuit to which a loadis connected.

It will be understood that the construction and arrangement of thecorona shield 92. and contact fingers 96 and 97 are such that a circuitthrough the switch blades 5353 maintained during the initial rotarymovement thereof to the open position and that this circuit ismaintained by the engagement of the contact fingers 96 and 97 with thecorona shield @2. for a time suthcient to permit the imultaneousoperation of the circuit interrupters 47-47 to open the circuit in atleast two places prior to the separation of the contact fingers 9-5 and97 from the corona shield 92 with the result that the only arcing thattakes place when they are separated is incident to the interruption ofthe relatively minute current that flows through the voltage dividingresistors in the circuit interrupters 4-747 when multigap units areused. Otherwise no arcingoccurs on opening the circuit.

As pointed out hereinbefore, the construction of the mechanism withinthe mechanism housings 5t 50 is such that on the continued rotation ofthe rotatable insulators 52-2 toward the open position, after the switchblades 5353 have separated, is such as to reclose the main and auxiliarycontacts 48 and 49 in the circuit interrupters t7d7 and to recock theoperating springs associated therewith. Thus in the switch open positionshown in FIG. 8, the circuit interrupters 474l7 are in the closedcircuit position but an air gap is provided between the mechanismhousings 5il5tl since the switch blades S3-"3 extend substantially atright angles thereto. Now, when the insulators 52 523 are rotated in theclosing direction, the switch blades 5353 are swung toward each otherand the circuit is initially completed by arcing or prestriking betweencorona shields 83-92 and 89-93. This is followed by the plate engagingthe contact fingers 86 in the sleet hood 87. Some arcing takes place, aspointed out, if the circuit is closed under load but the speed at whichthe switch blades 53-53 are closed is such as to reduce this arcing timeto a minimum. Because of the speed incident to the closing operation, itis essential that stop mechanism, such as that described herein, beemployed for arresting further movement of the switch blades 53-53 atthe end of their closing movements.

When each switch pole construction 44 is in the fully open position, asshown in FIG. 8, for example, both circuit interrupters 47-47 are intheir fully closed positions and their operating mechanisms are fullylatched. The operating springs therein are fully tensioned inpreparation for operating the respective main separable contacts 43-dtland auxiliary separable contacts 49-49 to interrupt the circuit in twoplaces by the circuit interrupters 47-47. In completing the circuit orclosing it by operation of each of the switch pole constructions 44 bymovement of the switch blades 5353 from their open positions to theirclosed positions shown in FIG. 7, a high speed is desired in order tocreate the least disturbance in the electrical transmission system towhich the switch construction is connected and to cause the least damageto the contact plate 85 and contact fingers 86. The use of the twoswitch blades 5353, which provides a center break arrangement, permitsthe desired fast closing movement. However, in combination with a singlecircuit interrupter, as described hereinafter, or two circuitinterrupters 47--47, it is essential that each switch pole construction44 be capable of closing a loaded circuit so that load currentimmediately flows. Also consideration must be given to closing on afault. In either case, the operation should be such that thecontinuously rated contacts comprising the contact plate 85 and thecontact fingers 85 are not damaged. Also the closing operation should beaccomplished without the creation of long uncontrollable arcs. It willbe recalled that the switch blades 53-53 are provided with coronashields 88-89 and 9293 and that corona shield 92 functions as an arcinghorn with the contact fingers 96 and 97 during the closing operation.They move toward each other at relatively great speed. In the pro-strikezone, the corona shields 3889 and 92-93 permit an arc to form betweenthem at a distance where arcing horns, if used, would not be in physicalcontact. In the operation of the switch pole construction 44 it isimportant for maintaining a proper operating sequence to bring theauxiliary metallic contact provided by the contact fingers 96 and 97into operation during the closing stroke to engage corona shield 92 sothat, when the switch blades 53-53 are fully closed, the contact plate85 is in complete engagement with the contact fingers 86 and the contactfingers 96 and 97 are in metallic contact with the corona shield 92which also functions as an arcing horn.

In the circuit opening operation of each switch pole construction 44 theinsulators 52-52 are rotated simultaneously because of the operatinglink 18 interconnecting them. The arrangement is such that each of thecircuit interrupters 47 is tripped at the same time because of themechanical coupling from each rotatable insulator 52 to the respectivesets of main separable contacts 48-48 and auxiliary separable contacts49-49. During these operations, and as a result of the rotation of therotatable insulators 52-52, the switch blades 53-53 begin to swing tothe open position. While this is taking place and while the circuit isbeing opened at two places by the circuit interrupters 47-47, it isimperative that the circuit be maintained through the switch blades53-53. The circuit therebetween is maintained by the contact fingers 96and 97 engaging the corona shield 92 while the switch blades 53-53themselves are physically being rotated toward the open position. Thiscontact engagement is maintained and the circuit therethrough remainsuninterrupted until after the circuit interrupters 47-47 have completedtheir circuit opening functions. Thereafter the contact fingers 96 and97 disengage the corona shield 92 when only the current flow through thevoltage dividing resistors in the circuit interrupters 47-47 is requiredto be interrupted. Since this current is relatively small, no particularproblem is involved with respect to it. The continued rotation of theinsulators 52-52 swings the switch blades 53-53 to the full openpositions shown in FIG. 8. During the latter part of the openingmovements of the rotatable insulators 52-52, as pointed out, the circuitinterrupters 47-47 are reclosed and their operating springs are recockedor recharged and all of the latches are reset.

FIGS. 9 and of the drawings show a modification of the switchconstruction illustrated in FIGS. 7 and 8 and described hereinbefore.Essentially the same arrangement is employed in the switch constructionshown in FIGS. 9 and 10 except that only a single circuit interrupter isemployed and the arrangement is intended to operate on a systemenergized at a lower voltage such as a voltage of the order of 115 kv.

As shown in FIGS. 9 and 10 the reference character 113 1 designates,generally, a switch construction in an underhung arrangement and carriedby support channels 102- 102 It will be understood that the switchconstruction 1111 can be mounted in an upright position or in a verticalposition as may be desired.

At one end of the support channels 1112-102 there is mounted astationary insulator support 103 while spaced therefrom are rotatableinsulator supports 1114- 104. Operating arms 1115-105 extend from therotatable insulator supports 104-104 and they are interconected by anoperating link 1%. The assembly is connected to an operating linkage108. It will be understood that it may be connected in the mannerhereinbefore de- 8 scribed in connection with FIGS. 1 and 2 of thedrawings as a part of a three pole switch construction to be operated bya switch operator, such as the switch operator 41 above referred to.

Depending from the stationary insulator support 1113 is a stationaryinsulator 1119 which carries a line terminal 119. The rotatableinsulators 111-111 are mounted on the rotatable insulator supports104-104. A stationary terminal 112 is carried by the lower end of theright rotatable insulator 111 and it corresponds to the stationaryterminal 56 previously described. A line terminal 113 is connected tothe stationary terminal 112 for connection to a circuit conductor.

Switch blades 114-114 are mounted for rotation with shafts 115-115 whichextend from the rotatable insulators 111-111 and are rotatabletherewith. Mounted on the left rotatable insulator 111 is a metallicmechanism housing 116 which is arranged to be electrically connected tothe switch blade 114 associated therewith in the manner previouslydescribed for the switch blade 53. Extending between the mechanismhousing 116 and the line terminal 119 is a circuit interrupter 117 whichcorresponds in construction to that of the circuit interrupters 47previously described.

The distal ends of the switch blades 114-114 carry separable contacts118 and 119. In order to prevent arcing between the contacts 118 and 119on opening or closing the circuit and to maintain it during the initialopening movement of the switch blades 114-114 and their final closingmovement, an arcing horn 120 is mounted on an arm 121 on one of theswitch blades 114 for engagement with a pair of arcing horns 122-122 onan arm 123 carried by the other switch blade 114.

In the switch construction shown in FIGS. 9 and 10 of the drawings theinsulators 111-111 are rotated in opposite directions to swing theswitch blades 114-414 out of contact engagement. Before they separate,the circuit interrupter 117 operates to open the circuit and interruptany are incident to the current flow therethrough. The continuedrotation of the insulators 111-111 is accompanied by rotation of theswitch blades 114-114 to the open circuit position to provide thedesired air gap in the circuit. While this is taking place the mechanismwithin the mechanism housing 16 is being recocked and the contacts ofthe circuit interrupter 117 are being reclosed.

What is claimed as new is:

1. A high voltage switch comprising, in combination, center breakisolator switch means including a pair of switch blades each rotatablymounted at one end about an axis for contact engagement with one anotherat their distal ends, at least one circuit interrupter connected inseries circuit relation with said isolator switch means, a firstrotatable insulator connected to one of said switch blades to rotateconjointly therewith about its axis and mechanically connected to saidcircuit interrupter, a sec- 0nd rotatable insulator connected to theother of said switch blades to rotate conjointly therewith about itsaxis, linkage interconnecting said insulators for simultaneouslyrotating them and said switch blades in opposite angular directions fromcircuit closed to circuit open pom'tion and for operating said circuitinterrupter to open the circuit, and interengaging contacts at saiddistal ends of said switch blades each including a load current carryingcontact member at least one of which extends arcuately and transverselyof the respective switch blade for maintaining the circuit between saidswitch blades during the initial opening movement of said switch bladesand until after the circuit is opened by said circuit interrupter.

2. The invention, as set forth in claim 1, wherein means operated by thefirst rotatable insulator reclose the contacts of the circuitinterrupter while the switch blades are being rotated to their openposition, and the one load current carrying contact engages the otherload current 9 carrying contact to complete the circuit by rotation ofsaid switch blades to the switch closed position.

3. The invention, as set forth in claim 1, wherein a stop cooperateswith each switch blade adjacent its axis of rotation to limit itsrotation at the ends of its movement to the switch own and switch closedpositions, and insulator means support each stop whereby each stop isenergized at the potential of the respective switch blade.

4. A high voltage switch comprising, in combination, center breakisolator switch means including a pair of switch blades each rotatablymounted at one end about an axis for contact engagement with one anotherat their distal ends, a circuit interrupter connected in series circuitrelation with each switch blade of said isolator switch means, a firstrotatable insulator connected to one of said switch blades to rotateconjointly therewith about its axis and mechanically connected to saidcircuit interrupter,

- a second rotatable insulator connected to the other of said switchblades to rotate conjointly therewith about its axis, linkageinterconnecting said insulators for simultaneously rotating them andsaid switch blades in opposite angular directions from circuit closed tocircuit open position and for operating the respective circuitinterrupter to open the circuit whereby the circuit is opened at twoplaces, and interengaging contacts at said distal ends of said switchblades each including a load current carrying contact member at leastone of which extends arcuately and transversely of the respective switchblade for maintaining the circuit between said switch blades during theinitial opening movement of said switch blades and until after thecircuit is opened by said circuit interrupters.

5. The invention, as set forth in claim 4, wherein means operated by therespective rotatable insulator reclose the contacts of the circuitinterrupters while the switch blades are being rotated to their openposition, and the one load current carrying contact engages the otherload current carrying contact to complete the circuit by rotation ofsaid switch blades to the switch closed position.

6. The invention, as set forth in claim 4, wherein a stop mounted oneach circuit interrupter cooperates with the respective switch bladeadjacent its axis of rotation to limit its rotation at the ends of itsmovement to the switch open and switch closed positions, and insulatormeans supports each circuit interrupter and the stop mounted thereonwhereby each stop is energized at the potential of the respective switchblade.

7. A high voltage switch comprising, in combination, an elongatedsupport, a stationary insulator stack at each end of said supportcarrying a line terminal, a pair of intermediate insulator stacksrotatably mounted on said support between the end insulator stacks, ashaft extending from each intermediate insulator stack and rotatabletherewith, a switch blade on each intermediate insulator stack connectedto the respective shaft to rotate conjointly therewith about its axisfor movement into or out of contact engagement with one another at thedistal ends thereof, a metallic mechanism housing rotatably mountingeach shaft and electrically connected to the respective switch blade, acircuit interrupter mounted on each stationary insulator stack andinterconnecting the line terminal thereof and the mechanism housingadjacent thereto, means for operating each circuit interrupter byrotation of the respective shaft, and means for simultaneously rotatingsaid intermediate insulator stacks to operate said circuit interruptersand open the circuit be tween said line terminals at two places followedby disengagement of said distal ends of said switch blades.

3. The invention, as set forth in claim 7, wherein stop means mounted oneach mechanism housing and energized at the potential of the respectiveswitch blade cooperate with the switch blade individual thereto forlimiting the rotation thereof at the ends of their movements to thecircuit open and circuit closed position respectively.

9. The invention, as set forth in claim 8, wherein the stop meansincludes a torsion bar for absorbing the impact grosses it) incident toarresting the switch blade by being stressed about its longitudinalaxis.

10. The invention, as set forth in claim 8, wherein each shaft projectsfrom opposite sides of its mechanism housing and carries a detent oneach projecting end to engage the stop means carried by the mechanismhousing and located in the path of the respective detent.

11. The invention, as set forth in claim 8, wherein additional stopmeans mounted on the elongated support cooperate with each rotatableinsulator stack for limiting the rotation thereof at the ends of theirmovements to the circuit open and circuit closed position respectively.

12. A high voltage polyphase switch comprising, in combination, aplurality of elongated supports in coplanar parallel spaced relationeach carrying one pole of the polyphase switch, each pole' including: astationary insulator stack at each end of its support carrying a lineterminal, a pair of intermediate insulator stacks rotatably' mounted onsaid support between the end insulator stacks, a shaft extending fromeach intermediate insulator stack and rotatable therewith, a switchblade on each intermediate insulator stack connected to the respectiveshaft to rotate conjointly therewith about its axis for movement into orout of contact engagement with one another at the distal ends thereof, ametallic mechanism housing rotatably mounting each shaft andelectrically connected to the respective switch blade, a circuitinterrupter mounted on each stationary insulator stack andinterconnecting the line terminal thereof and the mechanism housingadjacent thereto, means for operating each circuit interrupter byrotation of the respective shaft, and means for simultaneously rotatingsaid intermediate insulator stacks to operate said circuit interruptersand open the circuit be' tween said line terminals at two placesfollowed by disengagement of said distal ends of said switch bladeswhereby each is opened as aforesaid by the switch pole individualthereto.

13. A high voltage switch comprising, in combination, an elongatedsupport, a stationary insulator stack at one end of said supportcarrying a line terminal, first and second insulator stacks rotatablymounted on said support in spaced relation to each other and to saidstationary insulator stack, a line terminal carried by said secondinsulator stack, a shaft extending from each of said first and secondinsulator stacks and rotatable therewith, a switch blade on each of saidfirst and second insulator stacks connected to the respective shaft torotate therewith about its axis for movement into or out of contactengagement with one another at the distal ends thereof, meanselectrically interconnecting said line terminal carried by said secondinsulator and the switch blade associated therewith a metallic mechanismhousing rotatably mounting the shaft of said first insulator andelectrically connected to the switch blade individual thereto, a circuitinterrupter mounted on said stationary insulator stack andinterconnecting the line terminal thereon and said mechanism housing,means for operating said circuit interrupter by rotation of its shaft bysaid first insulator, means for simultaneously rotating said first andsecond insulator stacks to operate said circuit interrupter and open thecircuit between said line terminals followed by disengagement of saiddistal ends of said switch blades, and intcrengaging contacts on saiddistal ends of said switch blades each including a load current carryingcontact member at least one of which extends arcuately and transverselyof the respective switch blade for maintaining the circuit between saidswitch blades during the initial opening movement of said switch bladesand until after the circuit is opened by said circuit interrupter.

14. A switch for use on a high voltage alternating current power circuitcomprising, in combination, center break isolator switch means includinga pair of switch blades each rotatably mounted at one end about an axis,main contacts on the distal ends of said switch blades for 1 1 contactengagement with one another in their closed positions, load currentcarrying auxiliary contacts on said distal ends of said switch blades atleast one of which extends arcuately and transversely of the respectiveswitch blade for maintaining a circuit through said switch blades duringthe initial portion of their opening movement and the final portion oftheir closing movement, a circuit interrupter having seperable contactsconnected in series circuit relation with each switch blade of saidisolator switch means, means mechanically interconnecting said switchblades for rotating them conjointly to move said main contacts and saidauxiliary contact means out of and into contact engagement with eachother, means connected to each circuit interrupter for opening andclosing the contacts thereof, and operating means common to the switchblade operating means and to the circuit interrupter operating means toswing said switch blades to open position and to open said contacts ofsaid circuit interrupters while the circuit is maintained through saidswitch blades by said auxiliary contact means and thereafter disengagingsaid main contacts followed by disengaging said auxiliary contacts.

15. The invention, as set forth in claim 14, wherein a corona shield ismounted on the distal end of each switch blade in spaced relation toeach other and the respective main contacts whereby on closing movementof said switch blades when energized at normal voltage an arc isestablished between the corona shields in advance of the completion ofthe circuit through the auxiliary contacts.

References Cited by the Examiner UNITED STATES PATENTS 2,832,859 4/58Gilliland 200-48 3,012,123 12/61 Richardson et a1. 20048 3,030,481 4/62Gusson et al 20048 X KATHLEEN H. CLAFF Y, Primary Examiner. ROBERT K.SCI-IAEFER, Examiner.

7. A HIGH VOLTAGE SWITCH COMPRISING, IN COMBINATION, AN ELONGATEDSUPPORT, A STATIONARY INSULATOR STACK AT EACH END OF SAID SUPPORTCARRYING A LINE TERMINAL, A PAIR OF INTERMEDIATE INSULATOR STACKSROTATABLY MOUNTED ON SAID SUPPORT BETWEEN THE END INSULATOR STACKS, ASHAFT EXTENDING FROM EACH INTERMEDIATE INSULATOR STACK AND ROTATABLETHEREWITH, A SWITCH BLADE ON EACH INTERMEDIATE INSULATOR STACK CONNECTEDTO THE RESPECTIVE SHAFT TO ROTATE CONJOINTLY THEREWITH ABOUT ITS AXISFOR MOVEMENT INTO OR OUT OF CONTACT ENGAGEMENT WITH ONE ANOTHER AT THEDISTAL ENDS THEREOF, A METALLIC MECHANISM HOUSING ROTATABLY MOUNTINGEACH SHAFT AND ELECTRICALLY CONNECTED TO THE RESPECTIVE SWITCH BLADE, ACIRCUIT INTERRUPTER MOUNTED ON EACH STATIONARY INSULATOR STACK ANDINTERCONNECTING THE LINE TERMINAL THEREOF AND THE MECHANISM HOUSINGADJACENT THERETO, MEANS FOR OPERATING EACH CIRCUIT INTERRUPTER BYROTATION OF THE RESPECTIVE SHAFT, AND MEANS FOR SIMULTANEOUSLY ROTATINGSAID INTERMEDIATE INSULATOR STACKS TO OPERATE SAID CIRCUIT INTERRUPTERSAND OPEN THE CIRCUIT BETWEEN SAID LINE TERMINALS AT TWO PLACES FOLLOWEDBY DISENGAGEMENT OF SAID DISTAL ENDS OF SAID SWITCH BLADES.